Combinations of middleware series with "app.all" is broken since 4.18.0 #4913
Description
Like all app.METHOD(), app.all() takes callback functions that, according to http://expressjs.com/en/4x/api.html#app.all can be
- A middleware function.
- A series of middleware functions (separated by commas).
- An array of middleware functions.
- A combination of all of the above.
Which should make this example perfectly valid:
const express = require('express');
const app = express();
function mw1 (req, res, next) { next() };
function mw2 (req, res, next) { next() };
function mw3 (req, res, next) { next() };
function mw4 (req, res, next) { next() };
function mw5 (req, res, next) { next() };
app.all('/path',
mw1, // x
[
mw2, // x
[
mw3, // x
mw4 // x
],
],
[
mw5, // x
],
(req, res, next) => res.send('OK')
);
app.use((req, res) => res.status(404).send('Not Found'));
app.listen(3000);However with express@4.18.0 (and also 4.18.1):
curl -X GET http://localhost:3000/path # Works ("OK")
curl -X POST http://localhost:3000/path # Does not work (404)To make it work with POST, you can either
- Comment out any line with
// x - Change
app.alltoapp.post - Downgrade to express@4.17.3
This is a major bug for us since it changes the behaviour of app.all in a semver-minor version. I will try to figure out what causes this (must be between express 4.17.3 and 4.18.0).
I see that this is a quite extreme example of nested middleware invocations, but in our case these middlewares (and their combinations) come from different locations such as submodules, and thus cannot be written in a more linear way.